Scientists have discovered how breast cancer cells hibernate to evade treatment before ‘waking up’ years later.
The most common form of breast cancer can become dormant for decades but later cause a relapse that is more difficult to treat.
Now researchers hope that by discovering how, they can develop treatments to target and kill ‘sleeping’ cells, without the need for long-term hormone treatment.
Researchers from The Institute of Cancer Research, London, studied why oestrogen receptor positive (ER+) breast cancer – which makes up 80 per cent of all breast cancers – is able to return.
Scientists say there may be a way to target these ‘sleeping’ breast cancer cells before they wake up
Researchers looked at the role of an enzyme known as G9a and found that inhibiting it prevented cancer cells from becoming dormant and killed the cells that were already hibernating.
Professor Luca Magnani, of the Institute of Cancer Research, London, said they wanted to understand why endocrine therapy was not successful for all patients.
She said: ‘We wanted to better understand why breast cancer does return so we can hopefully find ways to stop it – so people don’t have to live in fear or face the devastating news of a relapse.
‘Our research identified a key mechanism used by cancer cells to evade therapy by remaining in a dormant state, hibernating before they “wake up” years later and begin to rapidly divide again.
‘I hope our early findings will next lead to research to target these dormant breast cancer cells so that one day, without the need for years of hormone therapy, patients can be sure that their cancer will not return.’
Oestrogen receptor positive (ER+) breast cancer is sensitive to the hormone oestrogen, which can assist cancerous cells to divide and grow.
Treatment often involves a combination of different therapies and surgery, including use of oestrogen blockers – known as endocrine therapy – for up to a decade.
Published in the journal Cancer Discovery, they discovered the mechanism by which the hormone treatment used to prevent breast cancer from returning triggers changes in some cancer cells, causing them to ‘hibernate’ instead of dying off.
While breast cancer survival has doubled in the UK over the last 50 years thanks to better detection and screening, there are still more than 11,000 deaths from this type of cancer every year.
Dr Tayyaba Jiwani, science engagement manager at Cancer Research UK – which funded the research, said: ‘Our research has made it increasingly clear that cancer cells can lie dormant in the body for many years before being triggered to reawaken, causing cancer to return.
‘This study uses an innovative approach to analyse the genetics of these dormant cells and gain important insight into the mechanisms leading to dormancy.
‘Although at an early stage, the findings reveal potential new targets for the development of innovative treatments that prevent breast cancer from coming back.’
Dr Simon Vincent, director of research, support and influencing at Breast Cancer Now, said: ‘This promising study gives vital clues into how cancer cells evade treatment and survive in an inactive state, and we look forward to seeing how this will inform future research.
‘Breast Cancer Now has recently committed to funding up to £1million of research into dormancy, and we hope that the findings from that research, alongside those published today, will help ensure people who have been treated for breast cancer are able to live happy, healthy lives without fear of the disease coming back.’
Breast cancer is one of the most common cancers in the world and affects more than two MILLION women a year
Breast cancer is one of the most common cancers in the world. Each year in the UK there are more than 55,000 new cases, and the disease claims the lives of 11,500 women. In the US, it strikes 266,000 each year and kills 40,000. But what causes it and how can it be treated?
What is breast cancer?
It comes from a cancerous cell which develops in the lining of a duct or lobule in one of the breasts.
When the breast cancer has spread into surrounding tissue it is called ‘invasive’. Some people are diagnosed with ‘carcinoma in situ’, where no cancer cells have grown beyond the duct or lobule.
Most cases develop in those over the age of 50 but younger women are sometimes affected. Breast cancer can develop in men, though this is rare.
Staging indicates how big the cancer is and whether it has spread. Stage 1 is the earliest stage and stage 4 means the cancer has spread to another part of the body.
The cancerous cells are graded from low, which means a slow growth, to high, which is fast-growing. High-grade cancers are more likely to come back after they have first been treated.
What causes breast cancer?
A cancerous tumour starts from one abnormal cell. The exact reason why a cell becomes cancerous is unclear. It is thought that something damages or alters certain genes in the cell. This makes the cell abnormal and multiply ‘out of control’.
Although breast cancer can develop for no apparent reason, there are some risk factors that can increase the chance, such as genetics.
What are the symptoms of breast cancer?
The usual first symptom is a painless lump in the breast, although most are not cancerous and are fluid filled cysts, which are benign.
The first place that breast cancer usually spreads to is the lymph nodes in the armpit. If this occurs you will develop a swelling or lump in an armpit.
How is breast cancer diagnosed?
- Initial assessment: A doctor examines the breasts and armpits. They may do tests such as a mammography, a special x-ray of the breast tissue which can indicate the possibility of tumours.
- Biopsy: A biopsy is when a small sample of tissue is removed from a part of the body. The sample is then examined under a microscope to look for abnormal cells. The sample can confirm or rule out cancer.
If you are confirmed to have breast cancer, further tests may be needed to assess if it has spread. For example, blood tests, an ultrasound scan of the liver or a chest X-ray.
How is breast cancer treated?
Treatment options which may be considered include surgery, chemotherapy, radiotherapy and hormone treatment. Often a combination of two or more of these treatments are used.
- Surgery: Breast-conserving surgery or the removal of the affected breast depending on the size of the tumour.
- Radiotherapy: A treatment which uses high energy beams of radiation focused on cancerous tissue. This kills cancer cells, or stops them from multiplying. It is mainly used in addition to surgery.
- Chemotherapy: A treatment of cancer by using anti-cancer drugs which kill cancer cells, or stop them from multiplying.
- Hormone treatments: Some types of breast cancer are affected by the ‘female’ hormone oestrogen, which can stimulate the cancer cells to divide and multiply. Treatments which reduce the level of these hormones, or prevent them from working, are commonly used in people with breast cancer.
How successful is treatment?
The outlook is best in those who are diagnosed when the cancer is still small, and has not spread. Surgical removal of a tumour in an early stage may then give a good chance of cure.
The routine mammography offered to women between the ages of 50 and 70 means more breast cancers are being diagnosed and treated at an early stage.
For more information visit breastcancernow.org or call its free helpline on 0808 800 6000
Source: Mail Online
